Apparatus for the manufacture of twist drills



Dec. 12 1950 H. w. DELANEY 3,

APPARATUS FOR THE MANUFACTURE OF TWIST DRILLS Original Filed May 31, 1941 6 Sheets-Sheet 1 lllll IN V ENTOR.

I ffm'y' W Ddan y BY D 1950 H. w. DELANEY 2,533,227

APPARATUS FOR THE MANUFACTURE OF TWIST DRILLS Original Filed May 31, 1941 6 Sheets-Sheet 2 Dec. 12, 1950 H. w. 'DELANEY 2,533,227

APPARATUS FOR THE MANUFACTURE OF TWIST DRILLS Original Filed May 31, 1941 6 Sheets-Sheet 3 INVENTOR ffa/ y l4. Dela/ Dec. 12, 1950 H. w. DELANEY 2,533,227

.APPARATUS FOR THE MANUFACTURE OF TWIST mums Original Filed May 31, 1941 6 Sheets-Sheet 4 YL A 21 E: ao' I j Q Q 27 28 INVENTOR.

#far y W Eda/15 8135mm, W,-W+W

Dec. 12, 1950 H. w. DELANEY 2,533,227

APPARATUS FOR THE MANUFACTURE OF TWIST DRILLS Original Filed May 31, 1941 A 6 Sheet-Sheet 5 INVENTOR.

"#42 5! W Eek/11: 1 BYM 54M) 2m Dec, 12, 1950 H. w. DELANEY 2,533,227

APPARATUS FOR THE MANUFACTURE OF TWIST DRILLS Original Filed May 31, 1941 6 Sheets-Sheet 6 INVENTOR.

i 'atent ed Dec. 12, 19 5 6 UNITED STATES OFFICE 2,533,227"

APPARATUS FOR THE MaNUFAoT URE F TWIST paints.

HarryW. Delaney, Chicago, Ill

Original; application. May 31; 1941,. Serial No..

395,961, nowPatent No. 2,457,132,1datedDecember 28, 1948. Divided-and this application November 1, 1946, Serial No; 707,144

10 Claims in cross section than the finished size of the drill.

by means of rolling grcoves inthe stock, twisting; it and rolling the outside diameter. These twist;- ed pieces of vstock-'maybe made up in any; desired. length, for example, between fifteen an sixty' inches long. To complete the drill, ittis necessary to out these bars or" stock to any desired length and then finish thedrillszby hardening. drawing, sand blasting, grinding the..0uterdla mi-.-

eter, and pointing. This facilitatesthespeedy productionand-deliveryof drills cf oddtlengths.

Drillsmanufactured by the methoddisclosed herein have a manufacturingcostof. from one-- half to one-third the cost'of milled-type drills.- Contributing factors to this economy are: the;

small size of stock used. the high rolling speed possible, and the fine grain structure-given to the: steel by rolling whiehobviates thenecessity. of purchasing ground andpoli'shed steel. Iniaddi-r tion, long drills maybe made substantially as:

cheap as-short drills.

By means to be'described herein, avery hard. cutting edge is obtained. Anair blastisusedto: equalize the heat of thenbar stock preparatory toits beingtwisted so that twist. of therdrill willhe. uniform. In addition, rollsare providedwhieh: are adjustable in twodireetions to accommodate drills of variousdiameters, and-a novel .and' flexible twistingmeans is disclosed. Further .advan:.- tages of the method and apparatus wilL'be, apparent from the followingdescriptic-n.

In the accompanying drawings:

Figure 1 illustrates-a side andend view'oila.

bar of stockat the various stages Obits-manua facture into a completed drill.

Figure 2 is an .endviewof the. slab'bing rolls.

Figure 3 isan end view of therough grooving. rolls.

Figure 4. is a partial .end view of the finishing. rolls.

Figure 5 is ,a diagrammatic view showing that a. drill is: formed from the'stock of a; smaller d1!- ameterr Figures 6 and 'I are partialverticalviewsof a pair of cooperating rolls adjusted in diiierent' vertical and horizontal directions to. accommo date drills of different sizes. 2

mill.

Figure 9 is an end View of a rolling mill.

Figure 1D is a front elevation ofa'twisting machine.

Figure 11 is a side elevation of a twisting ma:

chine.

Figure 12 is a section on the line 52-4 2 of'Fig-- Figure 13 is a section on the line l3l3of1 Fig-' urel0'. Figure 14 is a vertical section of one twisting fixture used-on the twistingmachine, and taken' on-the line 55-4 4 of Figure '15;

Figure 15 is an end view of one twisting fixtureQ Figure 16 is an end view of the chuck showing it in open position.

Figure 1'? isan end'view of' the chuck showing it in close'dposition;

Figure 18' is a plan view of the rolling plates. Figure 19 is a vertical'section of the rolling plates taken on the line l9'.il of Figure 18,

Figure 2c is a cross section .of'thedrill showing the hook iormed'onxeach' cutting. edge in dotted.

lines.

Figure 21 isa perspective view of a portionoij a drill showing thev hook created by rolling be-. tween the plates of Figure. 19.

Figure 22 is a. perspective View of a portion of adrill showing the portions which are ground oiT.

after hardening to expose the cutting edge.

Thernethod of manufacturing twist drills to be described.hereincomprises the following op.-

erations: Rolling the bar stock to give it a flats;-

ened cross section, rollingthe flattened stock to flute it, twisting the. fluted stock, rolling the out-. side diameter, cutting to lengths if required,

hardening the twisted stock, and finishing the.v

drill. In the preferred method the steps of; roll.-

ingthe stock to fiuteit, twisting and rollingtheoutside diameter are preferably all performed in However, satisfactory results have: been-obtained where only the-steps of rolling theone heat.

stock to'flute it andtwisting. it are performed in oneheat. The stock: is. then annealed andthe. outside diameter, rolled. coldin this alternative In addition,- the above operations promethod. duoe beads-along alternate edges of the flutes which,, after.- hardening, have a portion thereof groundoff to produce a outtingaedge.

Figure 8 is'a partial front elevation" of a rolling.

The alcove. operations may, he periormed on blank of any,

desired length which later may be cut to desired drill length.

Referring to Figure l, a bar of stock is shown in progressive stages of its formation into a completed drill. The numeral 1 designates the bar stock from which the drill is to be made. This is illustrated as stock of circular cross section, but it is to be understood that stock of other cross section could be used. It should also be noted that the diameter of the stock is considerably less than the diameter of the finished drill. The numeral 2 designates the bar after it has passed through the slabbing rolls illustrated in Figure 2. The numeral 3 designates the bar after passing through the rough grooving rolls. At 4 the bar is shown after having passed through the finishing rolls illustrated in Figure 4. The numeral 5 designates the bar after the heat therein has been made uniform in a manner to be hereinafter described and the bar has been twisted. At 6 the bar is shown after the outside diameter has been rolled in the device shown in Figures 18 and 19. The finished and pointed drill is shown at 1.

The bar stock shown by numeral I of Figure l is heated to a suitable temperature, preferably between 1800 and 2100 F. to facilitate the mechanical working to which it is to be subjected by subsequent operations. In the preferred method all of the subsequent operations up to and including rolling the outside diameter are performed in this one heat. In an alternate method, however, satisfactory results have been obtained where only the steps up to and including twisting the stock are performed in this one heat. The stock is then annealed and the outside diameter rolled cold. After the bar stock is removed from the furnace it is fed to the slabbing rolls of Figure 2.

The first or slabbing rolls are shown in Figure 2. These rolls are preferably in the form of cooperating frnstums. One of the rolls 9 is Preferably provided with flanges l adapted to receive the cooperating roll II. The flattened stock is in a tilted position when it emerges from these rolls so that it is in proper position to be fed to the rough grooving rolls i2 and 13 of Figure 3. The stock is then fed through finishing rolls I4 and I of Figure 4. It should be noted that the rolls of Figures 3 and 4 cooperate to produce a pair of longitudinal flutes in the bar stock and to produce a bead on alternate edges of said flutes. No configurations on the surface of the rolls are necessary to produce these beads. They are formed by allowing the metal to flow freely in an outward direction between the spaced outer flanges of the cooperating rolls. If desired, the beads could be rolled thereon by a separate operation.

The rolls of Figures 3 and 4 are preferably mounted so that they are relatively adjustable in either a horizontal or vertical direction. As shown in Figures 6 and 7, such adjustment permits the reception of bar stock of larger diameter. The one set of rolls therefore may be used to produce drills of several desired sizes. The surfaces of rolls Hi and i5 of Figure 4 are adapted to roll the stock to the shape designated by numeral 5 of Figure 1. The rough grooving rolls of Figure 3 and the finishing rolls of Figure 4 are substantially identical except that the rolls of Figure 4 are positioned closer together.

Referring to Figure 5 it will be seen that the rolling operations just described increase the diameter of the drill over that of the original bar stock. The numeral 1 designates the bar stools 4 before rolling and the numeral 4 designates the drill after it has passed through the finishing rolls of Figure 4. Bar stock I also lengthens in rolling.

Figure 9 is an end view of a rolling mill showing the rolls it and i5 therein and Figure 8 is a partial side view of the same rolling mill. It will be noted that each pair of rolls is retained by a separate housing It. Each housing i6 is slidably mounted upon a base if provided with ways [8. It is thus apparent that the housings may be adjusted relative to each other so that the distance between pairs of rolls is variable. This permits shortening the distance between pairs of rolls to accommodate bars of stock of shorter length so that the stock may run con-- tinuously through the rolls. The customary stripper is shown at 16 to prevent adhesion of metal to the rolls.

Following the above described rolling operations and before twisting the bar of stoc air is applied to the rolled fluted stock to equalize the temperature throughout its length so that the twist will be uniform. The end of the bar which was nearer the door of the furnace in the heating operation will be cooler than the end which was deep in the furnace. The application of air to the hotter end overcomes this. An ordinary f air hose has been found quite satisfactory for i thereon and adapted to be actuated by the hydraulic cylinder 2| and piston (not shown). Twisting fixtures 22 are mounted upon a base member 23 fastened to the frame l9. The bar or drill to be twisted herein is shown at 5. This bar has each end retained in one of the twisting pinions gears. ing fixtures 22 are slidably mounted upon the fixtures 22. Reciprocation of the press head 20 in a vertical plane is transmitted to rotary movement of chucks within the twisting fixtures 22 by means of gear racks 24' and 25, and suitable It should be noted that the twistbase member 23. This permits bar 5 of different lengths to be accommodated. Splined shafts 26 and 21 transmit motion from pinion gears which engage the gear racks 24 and 25 to the twisting fixtures 22 and permit relative movement between the twisting fixtures and the splined shafts. The splinec'i shafts are rotatably mounted in suitable bearings as shown. It will be apparent that the amount of vertical movement of the head 28 deterimnes the number of revolutions of the chucks in twisting fixtures 22 and therefore the amount of twist in the drill 5. Suitable limit switches 28a and 29a are adapted to stop movement of the head when engaged by adjustable members 3&3 and 3i which reciprocate with the head. It is also desirable to provide a scale 32 and pointer 33 to indicate to the operator the lead or pitch that he is imparting to the bar being twisted. The scale 32 is fastened to the reciprocating head and the pointer is fastened to a stationary object, such as the frame The calibrations are preferably in terms of twist or pitch.

Figures 12 and 1B illustrate the means of converting the linear motion of the gear racks 24 and 25 into the desired rotation of splined shafts 26 and 2?. In Figure 12 a pinion gear 28 is keyed to the splined shaft 2? and engaged by the gear rack 25. In Figure 13 additional pinion gears must be provided so that the direction of rotation of the splined shaft will be opposite or Figures 18 and l9,might be said to be put there for the express purpose of termporarily taking the skin softness acquired in hot working the drill. The surfaces to be ground off are shown in Figure 22. The section which is cross-hatched is the final cross section of the drill with the hook and top surface of the bead removed.

Thus it can be seen that the method of manufacturing twist drills disclosed herein in conjunction with the apparatus described enables the production of twist drills at a greatly reduced cost through the use of small size stock and high rolling speed. The grain refinement which results from the working of the steel eliminates the necessity of puchasing ground and polished steel and the unique rolling operation which temporarily provides an excess of metal adjacent the cutting edge insures a uniformly hard cutting edge of long life.

What I claim is: r

1. An apparatus adapted to twist fluted bar stock comprising a pair of chuck elements each having a rotatable portion adapted to engage the ends of a bar of stock, power means to rotate said portion of the chuck elements whereby said bar of stock is twisted, each of said chuck elements comprising an outer housing, an inner chuck housing slidably mounted on said outer housing, said power means including a driving member on said outer housing slidably associated with the inner housing for rotating the inner housing when the driving member is actuated, said inner chuck housing containing fingers rotatable with said inner housing and having gripping means thereon adapted to engage the bar stock to be twisted, said housings being provided with a cylindrical opening adapted to receive the bar stock to be twisted, whereby rotation of said inner housing twisting of the bar stock and the slidable mounting of the inner chuck housing permits the twisting bar stock to shorten, means to automatically release said fingers and resilient means to return said inner housing to initial position.

2. An apparatus adapted to twist fluted bar stock comprising a pair of chuck elements each having a rotatable portion adapted to engage the ends of a bar of stock, power means to rotate said portion of the chuck elements whereby said bar of stock is twisted, each of said chuck elements comprising an outer unit and an inner unit slidably mounted on said outer unit, said inner unit comprising a rotatable outer housing and an inner housing, braking means to resist rotation of said inner housing, said inner housing containing fingers having gripping means thereon adapted to engage the bar stock to be twisted, cam means on said outer housing to actuate said fingers and gripping means when the outer housing is rotated relative to the inner housing to engage said bar stock, said outer unit and inner unit being provided with a cylindrical opening adapted to receive the bar stock to be twisted whereby transmission of the rotation of the outer housing to the inner housing is resisted by the braking means and the relative rotation between the housings cams the fingers into engagement with the bar stock and some rotation is transmitted to the fingers whereby the stock is twisted and the slidable mounting of the inner unit permits the twisting bar stock to shorten, means to automatically release said fingers and resilient means to return said inner unit to initial position.

3. The combination as set forth in claim 2 wherein said gripping means comprises a pair of opening, said pins being detachably mounted onsaid fingers to permit interchanging said pins with pins of difierent sizes to accommodate bar stock of various sizes.

4. Apparatus for use in the manufacture of twist drills comprising a pair of vertically spaced rolls adapted to flatten a length of heated round bar stock and feed it between one or more pairs of cooperating spaced rolls adapted to form flutes along the entire length of said bar stock and continuous beads along alternate edges of said flutes, a press having mounted thereon a pair of twisting chucks adapted to engage the ends of said fluted bar stock and twist it into drill shape, and a press having vertical plates adapted to roll said drill stock to a desired size and partially fiow the metal of said bead into said flutes, said apparatus being so positioned as to permit all said operations to be performed as a substantially continuous process without further heating of the originally heated bar stock.

5. An apparatus for forming twist drills comprising means for rolling a length of heated round bar stock of multiple drill length into a drill blank having flutes extending longitudinally along the entire length of said blank and beads along alternate edges of said flutes, means for gripping the ends of said drill blank in the fluted portions thereof and twisting said ends in 0pposite directions to produce a drill blank having helical flutes of uniform lead extending the length of the blank and a pair of parallel relatively movable plates adapted to contact only said beads and flow a portion of the metal of said bead inwardly to form hooks on said flute edges, all of said means being so positioned as to permit all of said operations to be performed as a substantially continuous operation without further reheating of the originally heated bar stock 6. The combination as set forth in claim 5 including means for applying a blast of air to localized portions of said blank before twisting to equalize the temperature of said blank from one end to the other so that the twist imparted by said twisting fixture will be uniform throughout the length of said bar.

'7. An apparatus for forming twist drills from a length of heated round bar stock of multipie drill length comprising a pair of cooperating rolls each having a narrow circumferential flange and a wide circumferential flange separated by a recess around the periphery of the rolls, said rolls being spaced apart and bisymmetric in relation to each other so that the wide flanges indent the stock to form longitudinal flutes along the entire length of the stock and the narrow flange of one roll cooperates with a portion of the wide flange of the other roll to permit the free flow of metal therebetween to form beads along the alternate edges of said flutes, a pair of chuck members for gripping the ends of said fluted bar in the fluted portions thereof and twist said ends in opposite directions to produce a spirally fluted blank, and a pair of spaced relatively movable plates for rolling said spirally fluted bar down to a desired diameter, said plates being adapted to contact the beads only and flow a portion of said beads inwardly to form hooks on the alternate edges of said flutes, said rolls, chucks, and sizing plates being positioned such as to permit all of said operations to be performed as a substantially continuous operation without further reheating of the originally heated bar stock.

8. An apparatus for twisting bar stock comprising a base, a shaft rotatably mounted on said base, means for rotating said shaft, a pair of twisting heads mounted on said base, a rotatable chuck member slidably mounted on each of said twisting heads, means on said heads having a driving connection with said shaft and arranged to rotate said chuck member when said shaft is rotated, said last-mentioned means being rotatably fixed on said twisting head and having a slidable driving connection with said chuck members, said chuck members being adapted to engage the bar stock to be twisted, whereby when said chuck members are engaged with the ends of a bar of stock and rotated to twist said stock, the chuck members are permitted to move axially to compensate for the shortening of the stock caused by twisting while said twisting heads remain stationary on said base.

9. The combination as set forth in claim 8 wherein said driving means on the twisting heads have a slidable connection with said shaft and including means for adjustably mounting said twisting heads on said base, whereby the distance between them may be adjusted to accommodate bar stock of various lengths.

10. An apparatus for twisting bar stock comprising a support member, a chuck member slidably mounted on said support member, said chuck member comprising an inner housing and an outer housing, driving means on said support slidably connected with said outer housing for rotating said outer housing, means on said inner housing for gripping the end of a bar of stock, said inner and outer housings being provided with a cylindrical opening to receive a bar of stock 10 to be twisted, means tending to resist rotation of the inner housing when the outer housing is rotated, and cam means on said outer housing providing a lost motion connection with the inner housing and arranged to actuate said gripping means to engage the end of the bar of stock inserted within said cylindrical opening when the outer housing is rotated, whereby when said outer housing is rotated said bar is twisted and the slidable mounting of the chuck members on the support members allows the twisting bar stock to shorten.

HARRY W. DELANEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 8,032 Shortau Jan. 8, 1878 234,362 Willams Nov. 9, 1880 392,119 Hardsocg Oct. 30, 1888 432,636 Moore July 22, 1890 1,106,928 Denk Aug. 11, 1914 1,341,636 Deschauer June 1, 1920 1,379,071 Wineman May 24, 1921 1,405,414 Hervig Feb. 7, 1922 1,463,594 Rust July 31, 1923 1,518,721 Wineman Dec. 9, 1924 1,543,608 Leidecker June 23, 1925 FOREIGN PATENTS Number Country Date 15,562 Great Britain July 12, 1902 

